Polymer composite materials based on the Moplen HP400R polypropylene matrix with a filler from walnut shell flour with 30, 40 and 50% content and 200-315 µm and 315-443 µm fraction were produced by the injection method. The effect of filler content was analysed on the processing properties of the composites such as: MFR Melt Flow Rate and the MVR Melt Volume-flow Rate, as well as the temperature of the filler flour decomposition using the TGA thermogravimetric analysis method. The following was also determined: density, hardness, tensile strength and stiffness modulus of elasticity of the materials in question. The obtained composite material was characterised by low density, which increased with the rising filler content. It was found that the applied natural filler has increased the hardness and stiffness modulus of the composite and decreased the tensile strength.
In this paper, we have studied the evolution of morphology and brazing behavior of Ag-28Cu alloy filler processed by high energy ball milling. The milling of the powder mixture was carried out for 40 h. The structural and morphological analyses were performed by the X-ray diffraction and scanning electron microscopy. The melting temperature of the braze filler was determined by differential thermal analysis. The filler wetting properties were assessed from the spread area ratio measurements on various Ti substrates. The results indicate that the ball milling can effectively depress the filler melting point and enhance the brazeability. The milled powder mixture showed Ag(Cu) solid solution with a crystallite size of 174-68 nm after 40 h. It was shown that the high energy ball milling can be a potential method to develop low temperature brazing fillers for advanced microjoining applications.
Throughout the world, considerable quantities of water treatment sludge (WTS) and sewage sludge (SS) are produced as waste. This study assessed in the laboratory, the possibility to use both waste products when they are incorporated as filler at 1% with relation to the total mass of a hot mix asphalt - HMA. To this end, both waste products were initially reduced to ash through a calcination process. Resistance tests under monotonic load (Marshall and indirect tension tests), and cyclic load (resilient modulus test) were applied on mixes that contained WTS and SS. Besides, moisture damage (modified Lotmman test), and abrasion (Cantabro) resistance were assessed. An analysis of variance (ANOVA) test was performed in order to verify if the results are statically equal or not to those of the control HMA. As a general conclusion, it is reported that both materials show a resistance increase under monotonic load and higher stiffness under cyclic load (cohesion) when they are incorporated into the mix as filler despite the fact that the asphalt content used was less than the control mix. However, some problems are observed associated with moisture damage resistance, and friction wear (adherence).